Views: 0 Author: Site Editor Publish Time: 2021-06-15 Origin: Site
The stability of softeners is more sensitive to PH value. In the general dyeing and finishing process, cotton fabrics need to be pre-treated, and the pre-treatment usually uses alkali or alkaline substances to remove impurities on the fabric. Some fabrics need to be mercerized. The alkali used in these processes enters the fiber and is not easy to be washed. The dyed with reactive dyes or vat dyes also use alkali, so the fabric surface may be alkaline during finishing.
After the polyester fiber is dyed with disperse dyes, it must be reduced and cleaned, especially when using sodium hydroxide and caustic soda for reduction cleaning. If the cleaning is not clean, the cloth surface will also be alkaline. Generally, ordinary silicone oil is not alkali resistant, and it is easy to demulsify under alkaline conditions. It will stick to the roller after a period of time during the padding softening process, which will cause silicone oil spots.
1. Before soft processing, the cloth surface must be washed with alkali agent.
2. Add acetic acid to the working fluid to maintain the PH=5～6 of the rolling bath.